Here's where to buy the film:
http://www.bhphotovideo.com/bh4.sph/FrameWork.class
No, you can't use an amber safelight or any other that I'm aware of with this panchromatic film. I've read where you can use dark green at some distance, but it's about as dim as no light at all.

Not sure about the infra-red. Personally, I'd try a sheet...throw it in developer, etc...and see if it is fogged.

There was a recent post here about Eske sheet film, made in Croatia. They still have b/w in the 2x3 size. Also I believe Ilford still makes 2x3 cut film. The Eske is available from http://www.jandcphotography.com/ .

I have developed an infrared imaging system called PhotoVision IR that would allow you to "see" your film as you cut it to size. If you were planning on cutting the film in a changing bag or tent then this system would do the trick. However, It would not work in a darkroom setting.